Many Internet heavy hitters, including Apple, Google, Microsoft, and Yahoo, along with privacy advocacy companies and security experts, are sending an open letter to President Obama asking him to kill any government action that would require tech companies to build backdoor access into their products’ data. But there’s one big tech firm that is missing from the list of signers: Amazon.

There’s a bit of history here. Edward Snowden specifically criticized Amazon last December for not entirely securing user activity on its site: user transactions are encrypted, but user searches aren’t. Wariness in the post-Snowden era even extends to Amazon Web Services, which some don’t see as secure post-Snowden, according to Reuters. Microsoft’s Azure cloud platform has gained some business over Amazon by giving clients more direct oversight of their data in the cloud, and has allowed its clients to use third-party data storage centers when client data can’t leave its home country, says Reuters.

The open letter to Obama calls for the White House to avoid requiring security backdoors that the government could access, arguing they would lead to foreign governments requesting, or hacking, the same access. While larger tech titans may be able to resist foreign influence, as Facebook and Google are challenging their lawsuits in Europe, smaller companies who signed the open letter like Twitter can (and have) buckled to foreign pressure and shut down services at foreign governments’ requests. Opening the door to user data via these backdoors would be even worse–which makes Amazon’s absence even more odd.

Update, May 22: Although Amazon is not going so far as to actually sign the statement, an Amazon Web Services spokesperson tells Fast Company, “We’ve told the drafters of the letter that we’re happy to be identified directly as a supporter” of the letter.